This invention relates to monomers, polymers and copolymers of vinylbenzyl ethers of polyhydric halogenated phenolic compounds.
Vinyl-terminated compounds are useful in preparing a variety of both thermoset and thermoplastic resins. Additionally, such compounds are useful comonomers in a variety of resin systems. The vinyl moieties are useful polymerization sites in free-radical induced and thermal-initiated polymerization reactions.
Aromatic nuclei are desirably included in the backbone of thermoset and thermoplastic resins because they provide both chemical and structural stability. Other useful moieties included in the backbones of such resins are halogens, such as bromine. The halogens are known to promote fire-resistance to compounds containing them.
In the U.S. Pat. No. 3,058,953, polymers and methods of preparing vinylbenzyl phenol ethers are disclosed. However, the monomers are monofunctional (i.e., they have only one vinyl moiety). In U.S. Pat. No. 4,116,936, polymers of polyvinylbenzyl ethers of polyphenols are disclosed. However, the compounds which are halogenated require a glycidyl bridging group between aromatic rings. In U.S. Pat. No. 4,180,680, methods for preparing halophenolvinylbenzyl ethers are disclosed. Unfortunately, the monomers are monofunctional.
An especially desirable family of thermoset resins is disclosed in U.S. Pat. No. 4,528,366. These resins are aromatic polycyanate resins which can exhibit a dielectric constant of below 3 at 10 kHz. Therefore, these resins are desirably employed in preparing laminates for electronic circuit boards. Such polycyanates have been copolymerized with ethylenically unsaturated monomers in U.S. Pat. Nos. 4,559,425 and 4,559,399. Other polycyanates have been copolymerized with maleimides and ethylenically unsaturated monomers, as described in U.S. Pat. Nos. 4,371,689; 4,393,195; 4,396,745; and 4,469,859. Unfortunately, such compositions require expensive and complicated processing steps and fail to provide a polycyanate resin which exhibits the desired degree of fire retardancy.
In U.S. Pat. No. 4,094,861, a non-inflammable polytriazene is disclosed. Unfortunately, such compounds do not exhibit as desirable physical properties of triazenes prepared with other polycyanates.
It would be desirable to have polyfunctional vinylbenzyl ethers of polyhydric halogenated phenolic compounds. It would further be desirable if such compounds could be copolymerized with other monomers, especially poly(arylcyanate) ester resins to impart fire-resistance to the cured compositions.